summaryrefslogtreecommitdiffstats
path: root/drivers/media/i2c
diff options
context:
space:
mode:
authorMarkus Pargmann <mpa@pengutronix.de>2015-12-14 12:41:51 -0200
committerMauro Carvalho Chehab <mchehab@osg.samsung.com>2016-01-25 15:15:34 -0200
commit28d5bdbe5c0adcc11b7b63e65cf002a1ebaf3ca4 (patch)
tree0b017872794686229c83eec48e46b2028e702940 /drivers/media/i2c
parentc1ae8f3ad8758b588b4ba02edcb8d413185a10d7 (diff)
downloadlinux-stable-28d5bdbe5c0adcc11b7b63e65cf002a1ebaf3ca4.tar.gz
linux-stable-28d5bdbe5c0adcc11b7b63e65cf002a1ebaf3ca4.tar.bz2
linux-stable-28d5bdbe5c0adcc11b7b63e65cf002a1ebaf3ca4.zip
[media] mt9v032: Add reset and standby gpios
Add optional reset and standby gpios. The reset gpio is used to reset the chip in power_on(). The standby gpio is not used currently. It is just unset, so the chip is not in standby. Signed-off-by: Markus Pargmann <mpa@pengutronix.de> Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de> Acked-by: Rob Herring <robh@kernel.org> Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Diffstat (limited to 'drivers/media/i2c')
-rw-r--r--drivers/media/i2c/mt9v032.c28
1 files changed, 28 insertions, 0 deletions
diff --git a/drivers/media/i2c/mt9v032.c b/drivers/media/i2c/mt9v032.c
index 2e1d116a64e7..501b37039449 100644
--- a/drivers/media/i2c/mt9v032.c
+++ b/drivers/media/i2c/mt9v032.c
@@ -14,6 +14,7 @@
#include <linux/clk.h>
#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/log2.h>
#include <linux/mutex.h>
@@ -251,6 +252,8 @@ struct mt9v032 {
struct regmap *regmap;
struct clk *clk;
+ struct gpio_desc *reset_gpio;
+ struct gpio_desc *standby_gpio;
struct mt9v032_platform_data *pdata;
const struct mt9v032_model_info *model;
@@ -312,16 +315,31 @@ static int mt9v032_power_on(struct mt9v032 *mt9v032)
struct regmap *map = mt9v032->regmap;
int ret;
+ if (mt9v032->reset_gpio)
+ gpiod_set_value_cansleep(mt9v032->reset_gpio, 1);
+
ret = clk_set_rate(mt9v032->clk, mt9v032->sysclk);
if (ret < 0)
return ret;
+ /* System clock has to be enabled before releasing the reset */
ret = clk_prepare_enable(mt9v032->clk);
if (ret)
return ret;
udelay(1);
+ if (mt9v032->reset_gpio) {
+ gpiod_set_value_cansleep(mt9v032->reset_gpio, 0);
+
+ /* After releasing reset we need to wait 10 clock cycles
+ * before accessing the sensor over I2C. As the minimum SYSCLK
+ * frequency is 13MHz, waiting 1µs will be enough in the worst
+ * case.
+ */
+ udelay(1);
+ }
+
/* Reset the chip and stop data read out */
ret = regmap_write(map, MT9V032_RESET, 1);
if (ret < 0)
@@ -954,6 +972,16 @@ static int mt9v032_probe(struct i2c_client *client,
if (IS_ERR(mt9v032->clk))
return PTR_ERR(mt9v032->clk);
+ mt9v032->reset_gpio = devm_gpiod_get_optional(&client->dev, "reset",
+ GPIOD_OUT_HIGH);
+ if (IS_ERR(mt9v032->reset_gpio))
+ return PTR_ERR(mt9v032->reset_gpio);
+
+ mt9v032->standby_gpio = devm_gpiod_get_optional(&client->dev, "standby",
+ GPIOD_OUT_LOW);
+ if (IS_ERR(mt9v032->standby_gpio))
+ return PTR_ERR(mt9v032->standby_gpio);
+
mutex_init(&mt9v032->power_lock);
mt9v032->pdata = pdata;
mt9v032->model = (const void *)did->driver_data;